NEW YORK (Reuters) - U.S. gasoline prices soared more than 6 percent to the highest level in more than two years and margins jumped 16 percent when markets opened on Sunday as Tropical Storm Harvey caused widespread flooding in Houston and shut down refineries.

Futures RBc1 surged 7 percent to the highest level since late July 2015 at $1.7799 a gallon while gasoline margins RBc1-CLc1 jumped as much 18.2 percent to a high of $19.91 a barrel.

At least 2 million bpd of Gulf refining capacity is currently offline and damage assessments at four Corpus Christi, Texas, area oil refineries were under way on Saturday, a first step toward resuming production. However, by Sunday, more refineries were shuttered as the threat of flooding grew.

U.S. heating oil HOC1 prices also rallied, rising as much as 3 percent to a high of $1.6681 a gallon.

Reporting by Devika Krishna Kumar in New York; Editing by Sandra Maler